Adjustable end wrench and locking means



1, 1967 w. c. CHAPMAN ADJUSTABLE END WRENCH AND LOCKING MEANS Filed Aug. 10, 1966 INVENTOR Mai 972, [25% W/L L MM c. CHAPMAN United States Patent 3,333,492 ADJUSTABLE END WRENCH AND LOCKING MEANS William C. Chapman, 6061 Brighton Road, Brighton, Mich. 48116 Filed Aug. 10, 1966, Ser. No. 571,492 6 Claims. (Cl. 81-362) This invention relates to hand tools and has particular reference to an adjustable end wrench with means for effecting micromatic adjustment and novel means to lock the jaws in position and under pressure.

An object of the invention is to improve the wrench which was disclosed in US. Patent 3,190,154, issued to me on June 22, 1965.

In the patent hereinabove referred to I disclosed the use of a set screw, which is threadedly mounted near the end of the toggle linkage, in order to get the micromatic adjustment on the worm gear spindle and the jaws.

I now propose to eliminate the set screw and obtain the micromatic adjustment by lengthening the worm gear spindle so that it extends beyond the edge of the handle and is in contact at all times with the end of the pressure member.

With my improved structure I am able to eliminate the set screw and other parts of the structure, thereby obviating the necessity of much of the machine work and simplifying the construction of the device and greatly reducing the cost of production.

An object of the invention is to provide a simplified locking mechanism for an adjustable end wrench, which employs a rolling pivot, which is received in a recess formed in the handle for effecting the locking action.

Another object of the invention is to provide a locking mechanism for an adjustable end wrench, which employs a forwardly moving action along substantially straight lines.

Another object of the invention is to provide locking means for an adjustable and wrench, with simplified means for unlocking the device.

The foregoing and other objects and advantages of the invention will become more apparent as the description proceeds, reference being made from time to time to the accompanying drawing, forming part of the within disclosure, in which drawing:

FIG. 1 is a plan View of the device embodying the invention, with parts broken away to show the relation of certain parts, and with parts shown in broken lines to indicate the adjusted position of the parts.

FIG. 2 is a fragmentary top plan view of the device shown in FIG. 1.

FIG. 3 is a section taken substantially on the line 33 of FIG. 1.

Referring now more particularly to the drawing, it will :be understood that in the embodiment herein disclosed, as in my previous disclosure, the worm gear rotates freely on the spindle, and the spindle, gear and jaws are always under spring tension in one direction in order to facilitate the quick and accurate primary adjustment of the jaws.

In the embodiment herein disclosed the reference character 7 indicates, in general, the handle of the device which is provided with an opening 8 for receiving the forefinger of an operator, as described hereinafter, and as a means whereby the wrench may be hung from a nail or hook positioned on a wall, or the like.

The handle 7 terminates in a fixed jaw 9, opposite to which is an adjustable jaw 10, which is provided with a rack portion 11, which reciprocates in a tunnel-like opening 12 formed in an enlarged portion of the handle 7.

The rack 11 is actuated by means of a worm gear 13, which is freely mounted for rotation on a spindle 14, the

latter being reciprocable in a suitable bore 15 formed in the enlarged portion of the handle 7.

A spring 16 is mounted in the bore 15 and is arranged to exert pressure on the end of the spindle 14 so that the spindle 14 is normally urged away from the spring 16. A second spring 17 is positioned around the spindle 14 and between the lower end of the worm gear 13 and the end of a recess 18 formed in the enlarged portion 19 of the handle member 7.

The spring 17 normally urges the worm gear 13 in the same direction that the spring 16 urges the spindle 14. The spring 17 holds the threads of the worm gear 13 snugly against the bottom of the teeth of the rack 11 (FIG. 1). The springs 16 and 17 hold these working parts in a close state in one direction and obviate any tendency of the parts to rattle, or vibrate, whenthe jaws 9 and 10 are not under work load.

The spindle 14 has an enlarged portion 20, the end 20A of which forms a shoulder which contacts the upper end of the worm gear 13 at the end opposite the spring 17 as hereinafter described.

The enlarged portion 20 of the spindle 14 is received in a counter bore 21 formed in the bore 15. The spindle 14 has a'portion 14A which at all times extends beyond the edge 7A of the handle.

The springl always maintains the end of the member 14A in contact with the pressure member 22, forming part of the locking linkage. The pressure member 22 is a heavy stamping, having a depressed central section 22A (FIG. 2), the under face of which contacts the end 14A of the spindle and serves as a sliding cam for exerting pressure on the spindle 14.

The pressure member 22 has a bi-furcated, depending portion 22B which straddles the handle 7 and is pivoted thereto, as at 23. The rear end 24 of the pressure member 22 is received in the bi-furcated portion 25 of the locking lever 26, and is pivoted thereto, as at 27.

Received on the inside of the bi-furcated portion 25 of the locking lever 26 is a roller 28, which is pivoted as at 29. The roller 28 normally rests on the top edge 30 of the handle 7 when the locking lever 26 is in unlocked position, as shown by the broken lines in FIG. 1, and as the locking lever 26 is moved toward the handle 7 the roller 28 will move forwardly and will ultimately come to rest in a recess 31 formed in the upper edge 30 of the handle 7. It will be understood that the rear wall 31A of the recess 31 is gradually inclined, which inclination serves as a cam as the roller 28 moves into and out of the recess 31.

It will also be understood that because of the short radius of the roller 28 and the short distance between the pivots 27 and 29 and the comparatively long locking lever a considerable leverage will be effected on the member 22 at the spindle.

The use of the rolling pivot, instead of straight levers as in a toggle hook-up, makes it easy to lock and unlock the mechanism. With the use of the rolling pivot on the inclined face of the recess, the locking of the parts is effected even before the free end of the locking lever is brought into contact with the handle and the roller is finally seated in the recess.

With the use of the rolling pivot substantially the same direction of force is maintained on the parts throughout the locking action. This is not true in toggle linkage wherein the center pivot has to pass over a high point to lock and release the parts.

Further as the roller 28 moves forwardly on the edge 30 of the handle, and on the cam Wall 31A, the cam on the under face of the pressure member 22 will slide on top of the spindle 14, exerting the final pressure on the spindle 14 to lock the jaws 9 and 10 against displacement from the work piece 32.

The handle 7has a heavy bead 33 around its entire length and the bi-furcated portion 25 of the locking lever 26 has an internal boss 34, which contacts the under edge of the bead 33 and serves as a stop to limit the upward movement of the locking lever 26 (FIG. 3).

When the locking lever is in the position shown by the solid lines in FIG. 1, the device is under full locking pressure. The locking lever may be released by the operator by inserting his forefinger through the opening 8, and using his thumb as at 35 to move the lever 26 away from the handle 7,thus effecting the release of the pressure on the jaws 9 and on the work piece 32, at the same time moving the roller 28 out of the recess 31 up the cam 31A to the unlocked position shown in FIG. 1.

In using the device the jaws 9 and 10 are first placed over the work piece 32 and an initial adjustment is made by turning the worm gear 13. During the initial adjustment the worm gear 13 and the jaw 10 and under the compression of the spring 17, which urges the worm gear and the jaw 10 in the direction away from the spring, and against the shoulder 20A formed on the spindle. This insures the quick and easy rotation of the worm gear on the spindle and the movement of the slidable jaw 10 to effect the initial adjustment. Further turning of the worm gear 13 slightly; depresses the spring 17 and moves the slidable jaw for the final adjustment. 7

When the locking lever 26 is then depressed the pres sure element 22 urges the spindle 14 against the compression of the spring 16, and at the same time the shoulder 20A contacts the upper face of the worm gear 13, causing it to move against the pressure of the spring 17 and against the teeth of the rack 11, to lock the jaws against the Work piece.

So long as the jaws 9 and 10 do not have a work piece between them the Worm gear 13 is free to rotate on the spindle 14, so that it is an easy matter to adjust the jaw 10 even though the locking lever 26 is depressed.

As soon as a work piece is received between the jaws and the initial adjustment is made, and when the locking lever 26 is depressed, the pressure member 22 acting on the spindle 14 through the shoulder 28, and the worm gear 13, causing the jaws to be locked in tight position against the lever.

It is believed the operation of the device is obvious from the foregoing.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In an adjustable end wrench of the character described having a handle and a spring biased reciprocable spindle with a worm gear freely rotatable thereon, the combination of a pivoted pressure member, one end of which is in contact with one end of said spindle, a locking lever pivoted to the opposite end of pressure member and arranged to exert leverage on the opposite end of said pressure member, said lever having a rolling pivotin contact with one edge of said handle.

2. The structure of claim 1, in which said handle has a recess for receiving said rolling pivot.

3. The structure of claim 1, in which said handle has a recess for receiving said rolling pivot, said recess having at least one inclined wall which serves as a cam for said rolling pivot.

4. The structure of claim 1, in which said handle has a recess for receiving said rolling pivot, said handle and said recess being provided with a marginal bead, and stop means on said locking lever arranged to contact said head to limit the movement of said lever.

5. The structure of claim 1, in which said spindle is always in contact with said pressure member and said pressure member has a cam face formed thereon for exerting pressure on said spindle.

6. The structure of claim 1, in which said locking lever and said handle are of substantially equal length, the said handle having a finger hole therein and said locking lever having a rounded end for receiving the thumb of an operator.

References Cited UNITED STATES PATENTS 6/1965 Chapman 81-315 

1. IN AN ADJUSTABLE END WRENCH OF THE CHARACTER DESCRIBED HAVING A HANDLE AND A SPRING BIASED RECIPROCABLE SPINDLE WITH A WORM GEAR FREELY ROTATABLE THEREON, THE COMBINATION OF A PIVOTED PRESSURE MEMBER, ONE END OF WHICH IS IN CONTACT WITH ONE END OF SAID SPINDLE, A LOCKING LEVER PIVOTED TO THE OPPOSITE END OF PRESSURE MEMBER AND ARRANGED TO EXERT LEVERAGE ON THE OPPOSITE END OF SAID PRESSURE MEMBER, SAID LEVER HAVING A ROLLING PIVOT IN CONTACT WITH ONE EDGE OF SAID HANDLE. 